Rotating electric machines employing stator mounting of windings are popular. A rotating electric machine of this kind is usable as an electrical motor that enables rotation of a rotor by passing three-phase alternating currents through windings on a stator to create magnetic fields. Moreover, in the case of a rotating electric machine employing rotor mounting of permanent magnets, the rotating electric machine is usable as a generator to store regenerative current that is caused by magnetic fields created at the windings (coils) by turning the rotor into the vehicle battery or the like.
As described above, the rotating electric machine with windings through which three-phase alternating currents pass employs a circuit arrangement in which the windings are connected to form the “Y” (or “star”) configuration with one ends connected to three voltage sources of three-phase alternating currents, respectively, and the other ends connected to a neutral point (see JP2009-232650A, called “Patent Literature 1” below).